Large diameter pipe cutting device

ABSTRACT

This invention relates to a large diameter pipe cutting device for cutting a large diameter steel or cast pipe by moving a cutting machine vertically and bilaterally along the outer periphery of the pipe, said cutting machine including a twoparallelly opposed legged plate support and a cutter driven by an electric motor, said plate support being guided along the outer periphery of the pipe by a bush chain or chains wound tightly on the pipe in a relation forming a vertical plane meeting at right angles with the axis of the pipe.

United States Patent Ono [151 3,704,516 [451 Dec. 5, 1972 1541 LARGEDIAMETER PIPE CUTTING DEVICE [72] Inventor: Teizo Ono, 4-32 ItachiboriKitadori Nishiku, Osaka, Japan [22] Filed: Oct. 22, 1970 [211 App]. No.:82,892

[52] US. Cl ..30/96, 269/2 [51] Int. Cl. ..B23d 45/ 12, B23d 47/02 [58]Field of Search ..30/92, 93, 94, 96, 97, 102;

[56] References Cited UNITED STATES PATENTS 4/ 1939 Gottwald ..269/27/1942 Levey ..30/97 Hentke ..30/92 Galezniak ..30/96 UX PrimaryExaminer-Theron E. Condon Attorney-Alfred W. Breiner [57] ABSTRACT Thisinvention relates to a large diameter pipe cutting device forncutting alarge diameter steel or cast pipe by moving a cutting machine verticallyand bilaterally along the outer periphery of the pipe, said cuttingmachine including a two-parallelly opposed legged plate support and acutter driven by an electric motor, said plate support being guidedalong the outer periphery of the pipe by a bush chain or chains woundtightly on the pipe in a relation forming a vertical plane meeting atright angles with the axis of the pipe.

5 Claims, 6 Drawing Figures LARGE DIAMETER PIPE CUTTING DEVICE Thisinvention relates to a device for cutting a steel or cast pipe having anouter diameter of 0.8 to 1.5 meters along a vertical plane making aright angle with the axis of the pipe.

Among conventional methods of mechanically cutting a large diameter pipethere is included a method of'cutting a large diameter pipe by clampingthe pipe with the chuck of a large-size cutting device and turning acutter along the periphery of the pipe, but the cutting device accordingto said method is too large to be carried by a workman and accordinglyit cannot be used outside of the work shop where it is set. On the otherhand, it often happens that this kind of cutting work is needed at theplace where piping work is done. In such a case it is a practice torepeat partial cutting of a large diameter pipe with a portable cutterin the hand while turning the pipe. As the partial cutting of the kinddescribed is repeated by a workman through his knack, the edge of thepipe cut is liable to incline, with the result that the last kerf isoften brought out of alignment with the first kerf and this is turn notonly distorts the cutting plane of the pipe but also wasteful trouble isinvolved. Also, a large-size chain type cutter may be used, but cuttingof the large-size pipe with the largesize cutter requires many workmenand a great deal of time. That means reduced efficiency. Furthermore,the use of a cutting torch is possible, but as the surface of a torchcut pipe is rough, it must be given the last finish by hand.

This invention has eradicated the disadvantages inherent in theconventional methods of cutting a large diameter pipe at the place wherepiping work is done and provides a method of cutting the pipe in themanner in which cutting is always made in a vertical plane making arightangle with the axis of the pipe.

A primary object of this invention is to provide a cutting device whichmakes it possible to easily bring the cutting plane of a pipe intoagreement with a vertical plane meeting at right angles with the axis ofthe pipe.

Another object of the invention is to provide a cutting device that canbe carried by a workman so as to be used at the place where piping workis done.

Another object of the invention is to provide a cutting device which,when one type of cutter is changed for another type, can form in a pipea kerf for use as a bevel end adapted to be welded with other pipe.

Still another object of the invention is to provide a cutting devicecapable of forming a smooth cut plane.

A preferred embodiment of the invention will now be described withreference to the accompanying drawing in which:

HO. 1 is a front view of a cutting device equipped with a cutter guidedby one bush chain that is wound on a large diameter pipe;

FIG. 2 is a side view of FIG. 1;

FIG. 3 is a side view of the cutting device in which two bush chains areused;

FIG. 4 is a fragmentary longitudinal sectional view showing a cutterused in forming a pipe end for welding with another pipe and the pipeend cut away into a bevel end;

FIG. 5 is a fragmentary front view of the bush chain; and

A description will now be made of the invention with reference to anembodiment thereof. When a large diameter pipe 1 to be hereinafterreferred to simply as a pipe is placed on supporting rollers 2 and abush chain 4 large in width andslightly longer than the outer peripheryof the pipe 1 is caused to be supported on the upper half part of thepipe, the chain 4 depends vertically with respect to the axis of thepipe 1 by its own empty weight. Furthermore, depending upon the case,two narrow chains as shown in FIG. 3 may be allowed to depend parallellyand spacedly apart a distance equal to the distance of the outsides of atwo-legged plate support 3 along the outer periphery of the pipe.Thereafter, the lower ends 8 and 8 of L-shaped connecting plates 6 and 6are respectively fitted over a spindle Sat one end of the chain andanother spindle 5 positioned closest to said spindle 5 at the other endof the chain, and the connecting plates 6 and 6 are tightened at theupper ends by bolts and nuts to make the chain grip securely the entireperiphery of the chain. The same is also the case with two chains usedas shown in FIG. 3.

An electric motor is placed .in a cutter case 9 and a cutter 10 such asan emery wheel is mounted to the end of the motor shaft in such a mannerthat it is replaceable with any desired cutter. Beneath the case 9 isprovided a two-legged plate support. The plate support 3 is of theconstruction in which the distance at which the two legs of the supportface each other is such that the plate support 3 comes into closecontact with the outside of the broad chain and with the inside of eachof the two narrow chains. Also, as the case 9 is allowed to make freevertical movement with respect to the plate support 3, the cutter can bemoved vertically and bilaterally.

In the present device it is an extremely important task to wind thechain or chains on the pipe in a vertical plane meeting at right angleswith the axis of the pipe, and therefore it is only necessary to make athick semicircular steel band straddle over the pipe, said thicksemi-circular steel band having a width equal to the width of the platesupport 3 and coming into tight contact with the periphery of the pipe,and to wind the chain on the pipe so as to bring the chain into closecontact with the side of the band. Preferably this method may beresorted to when two chains are used.

Now in operation. The pipe is placed on the supporting rollers 2, thecutter 10 mounted on the shaft of the motor is rotated, and the case 9is manually lowered to make the cutter touch the outer surface of thepipe. When the case is gradually lowered and the cutter cuts its waythrough the pipe to expose its cutting edge under the inner periphery ofthe pipe, all that is necessary is to rotate the pipe progressively. Ifit is intended that the pipe being thus cut is welded with other pipe ofthe same diameter, the use of a cutter having the configuration shown inFIG. 4 will provide a bevel end.

As this invention is of the construction described in which a bush chainis wound on a large diameter pipe and the plate support of the cuttingmachine guided by the chain is moved exactly along the pipe peripherymeeting at right angles with the axis of the pipe to cut the pipe byrepeating partial cutting of the pipe, it can not only bring the lastkerf always into alignment with the first kerp to provide a fine andexact pipe end forming a vertical plane with respect to the axis of thepipe but also can shorten a cutting time in a substantial degree bysimplifying piping work and increasing efficiency in the work.

lclaim:

1. A large diameter pipe cutting device comprising one broad chainformed by articulately connected links and spindles, a plurality ofoutermost ones of said links on each side of said chain lie in a commonplane with said planes being parallel to each other and normal to thepipe axis, said outermost links defining guide surface means for guidinga cutting machine cutter relative to a pipe to be cut thereby, meansbetween said planes for securing said chain in encircled relationship toa pipe thereby precluding obstructions along said outermost links, acutting machine carrying said cutter, a support for said cuttingmachine, said support including a pair of spaced guiding legs, and saidspaced guiding legs being in external embracing contacting relationshipto said outermost links thereby being guided upon relative rotationbetween said chain and said support.

2. The large diameter pipe cutting device as defined in claim 1including means mounting said cutting machine upon said support forradial sliding movement relative to said pipe.

3. A large diameter pipe cutting device comprising a pair of chains eachformed by articulately connected links and spindles, a plurality ofoutermost ones of said links on each side of each chainlie in a commonplane with said planes being parallel to each other and normal to thepipe axis, said pair of chains being mounted in encircled relationshipto a pipe and in spaced parallel relationship to each other, saidoutermost links of said chains most adjacent each other defining guidesurface means for guiding a cutting machine cutter relative to a pipe tobe cut thereby, a cutting machine carrying said cutter, a support forsaid cutting machine, said support including a pair of spaced guidingsurfaces, and said spaced guiding surfaces being in sandwichedrelationship between and guiding contact with said most adjacentoutermost links thereby being guided upon relative rotation between saidchains and said support.

4. The large diameter pipe cutting device as defined in claim 3including means mounting said cutting machine upon said support forradial sliding movement relative to said pipe.

5. The large diameter pipe cutting device as defined in claim 3including means between the outermost links of each chain for securingsaid chains in encircled relationship to a pipe thereby precludingobstructions along said adjacent outermost links.

1. A large diameter pipe cutting device comprisiNg one broad chainformed by articulately connected links and spindles, a plurality ofoutermost ones of said links on each side of said chain lie in a commonplane with said planes being parallel to each other and normal to thepipe axis, said outermost links defining guide surface means for guidinga cutting machine cutter relative to a pipe to be cut thereby, meansbetween said planes for securing said chain in encircled relationship toa pipe thereby precluding obstructions along said outermost links, acutting machine carrying said cutter, a support for said cuttingmachine, said support including a pair of spaced guiding legs, and saidspaced guiding legs being in external embracing contacting relationshipto said outermost links thereby being guided upon relative rotationbetween said chain and said support.
 2. The large diameter pipe cuttingdevice as defined in claim 1 including means mounting said cuttingmachine upon said support for radial sliding movement relative to saidpipe.
 3. A large diameter pipe cutting device comprising a pair ofchains each formed by articulately connected links and spindles, aplurality of outermost ones of said links on each side of each chain liein a common plane with said planes being parallel to each other andnormal to the pipe axis, said pair of chains being mounted in encircledrelationship to a pipe and in spaced parallel relationship to eachother, said outermost links of said chains most adjacent each otherdefining guide surface means for guiding a cutting machine cutterrelative to a pipe to be cut thereby, a cutting machine carrying saidcutter, a support for said cutting machine, said support including apair of spaced guiding surfaces, and said spaced guiding surfaces beingin sandwiched relationship between and guiding contact with said mostadjacent outermost links thereby being guided upon relative rotationbetween said chains and said support.
 4. The large diameter pipe cuttingdevice as defined in claim 3 including means mounting said cuttingmachine upon said support for radial sliding movement relative to saidpipe.
 5. The large diameter pipe cutting device as defined in claim 3including means between the outermost links of each chain for securingsaid chains in encircled relationship to a pipe thereby precludingobstructions along said adjacent outermost links.